DC motor
The market offers different types of electric motors, therefore, control strategies depend on their structure. The stator of a DC permanent magnet motor consists of two or more magnetic poles. The rotor, on the other hand, consists of windings connected to mechanical switches.
The abbreviation BLDC (brushless DC) refers to a synchronous brushless motor with permanent magnets that rotate around a fixed armature: their rotor and stator rotate at the same frequency. The switching between the rotor and the motor stator is not mechanical, but electronic. Unlike brushed DC, it does not require a connection to the motor shaft to operate.
In brushed motors, the rotor and brushes generate a constantly changing current by reversing magnetic fields. In brushless motors, the current reversal is achieved electronically through a set of power transistors (typically IGBTs) controlled by a microcontroller. A key challenge in operating these motors is understanding the exact position of the rotor. Only then can the controller determine which stage to operate. The rotor's position relative to the stator is typically obtained using Hall effect sensors or optical sensors.
Typical applications of brushless DC motors are those where components (brushes) cannot be replaced, because these systems are sealed (e.g., hard drives).
The MAX14871 DC motor driver provides a simple driver for brushed motors operating from 4.5V to 36V. Its pump-free charging design reduces external components and lowers supply current.
The Maxim MAX14871 full-bridge DC motor driver provides a simple, low-power solution for driving and controlling brushed motors. The motor can operate within a 4.5V-36V voltage range. The driver features very low on-resistance, reducing power consumption during dissipation. The device employs a charge-pump-less design to reduce external components and supply current. Integrated current regulation allows users to define the peak start-up motor current with minimal external components. The MAX14871 includes three current regulation modes: fast decay, slow decay, and a 25% current ripple mode. Current regulation based on the 25% ripple simplifies design and makes regulation independent of motor characteristics.
The RHOM Semiconductor BD63005AMUV is a three-phase brushless motor driver with a rated supply voltage of 33V and a rated output current of 2A (3.5A peak). It generates a drive signal from a Hall sensor and drives a PWM signal via an input control signal. Furthermore, it can use either 12V or 24V power and features a variety of control and integrated protection functions, making it suitable for a wide range of applications.
The BD63005AMUV, BD63006MUV, and BD63007MUV three-phase brushless motor drivers offer advantages such as low power consumption and low output on-resistance. With a maximum standby current of 1.7mA and a maximum operating line current of 8.4mA, they meet the low power consumption requirements of various applications. The typical total output on-resistance of the BD63005AMUV and BD63007MUV is 0.17Ω, while that of the BD63006MUV is 0.8Ω. They can be powered by either 12V or 24V. These three chips feature various control functions, including built-in 120° commutation logic and power-saving circuitry, enabling low on-resistance DMOS output. They also offer various fault protection functions, such as current limiting (CL), thermal shutdown (TSD), overcurrent protection (OCP), undervoltage lockout protection (UVLO), overvoltage protection (OVLO), and motor lockout (MLP), making them suitable for a wide range of applications.
Brushless DC motors (BLDC) are very popular in home appliances and consumer electronics. These applications require high efficiency standards, thus necessitating better technology to minimize overall power loss.
The power-integrated BridgeSwitch driver series utilizes high-end and low-end advanced FREDFET (Fast Recovery Diode Field Transistor) series, achieving efficiencies exceeding 98.5% in brushless DC motor drive applications up to 300 W. This high efficiency, distributed thermal footprint architecture eliminates the need for heatsinks, thereby reducing system cost and weight.
